Kellenberg Memorial High School is a Roman Catholic college-preparatory school in Uniondale, Long Island, New York. Kellenberg is the second Marianist school on Long Island and prides itself on high academic standards combined with a strong focus on faith.

Kellenberg is accessed through the main entrance across from RXR Plaza on Glenn Curtiss Blvd. Although the lobby was originally designed as the main entrance, the school is oriented toward its north entrance. The north entrance of the school features a mural of the Holy Family, including a depiction of Jesus as a teenager, designed by artist Yan Rieger in 1997, in honor of the school's tenth anniversary. Students and Marianists assisted the artist and his wife with the execution of the mural. Kellenberg Memorial has four athletic fields, baseball, football, softball etc., each is separately named after one of the four gospel writers. The school also is the caretakers of

A new artificial turf field was installed during the summer of 2010. This marks a series of campus improvements and expansions that will take place throughout 2010 and 2011.